iOS (Jailbroken): The lock screen on the iPhone hasn't changed much since its inception, but if you're looking to give it a slight overhaul without changing everything, SubtleLock is a simple little jailbreak tweak that gives your lock screen a lot more room to breath.

SubtleLock reduces the size of the clock, stuffs the date into the corner, and shrinks down the "slide to unlock" area. The benefit here is that it offers a heck of a lot more room for notifications when they come in. It also fully supports other apps like LockInfo and Dashboard X to give you more room to display useful info on your lock screen.